Agreed. The R7 250E/7750, which is a 55W part, was made available in single-slot low profile, there's no excuse for the RX 550, which draws a few less watts than that, to have a similar solution.
EDIT: Also, given that the GTX 750 and GTX 750 Ti have a TDP of 55 and 60W respectively, likewise, there doesn't seem to be any good reason for a single-slot cooling solution on a low-profile card for them, either. Had there been, I likely would've purchased one of those cards in lieu of the somewhat difficult to find 250E/7750 single-slot-low-profile.
Also agreed that the higher end Intel Integrated graphics (is it called the 630?) might make an interesting comparison, though I can't argue with the fact that it's unlikely that someone with a high-end modern Intel CPU would be playing in the low-end graphics market.
I'm really looking forward to the update in the hierarchy chart, not just to see where exactly they place the 1030, but to see if other's in surrounding tiers get shuffled slightly. Based on its current position in the chart, I would've assumed the RX550 would've performed worse than it did here.